Mammography is a type of x-ray specifically designed to view the breast. The x-ray films produced by mammography, called mammograms, can find small tumors or irregularities in the breast.

There are two main types of mammography: screening and diagnostic. A screening mammogram is a general screening test for women with no symptoms. A diagnostic mammogram is performed if the screening mammography identifies a suspicious area or if a person feels a lump in their breast or has other unusual symptoms. Diagnostic mammography usually takes more views (pictures) of the breast.

Mammography is such an important tool in breast cancer detection that a federal law, the Mammography Quality Standards Act, was passed in 1992 to make sure mammography machines are serviced regularly and operating at optimal levels and technicians and radiologists performing mammography have current training. This law also requires mammography facilities to mail women their results within 30 days of the test.

Over the years, there have been advancements in mammography, and today the doses of radiation used are much lower and the images much clearer than previous technology. The latest technology developments include digital mammography, in which the image is recorded on a computer instead of on film, making images easier to store and retrieve. As with other digital x-ray technology, digital mammography is still being refined.

The medical team

Mammography is performed by a mammogram technologist who is specially trained to operate the mammography equipment. Most mammogram technologists are women. You and the technologist will be alone in the room during the procedure.

A mammogram is reviewed by a radiologist, a medical doctor who performs and interprets imaging tests to diagnose disease.

Questions to ask your doctor before the mammogram

Before having the mammogram, you should discuss with your doctor any breast symptoms or specific problems you're experiencing. Also, consider asking your doctor the following questions:

• Who will perform the mammogram?
• Does the facility specialize in performing mammography?
• Are there any risks associated with mammography?
• Should I bring previous mammogram results with me to this examination?
• When and how will I learn the results?
• Who will explain the results to me?
• What further tests will be necessary if the test results are unclear or indicate cancer?

Tell your doctor if you are pregnant or breast-feeding. In both cases, your doctor will probably tell you not to have a routine screening mammogram.

Preparing for the procedure

On the day of your mammogram, do not use deodorant, antiperspirant, powder, lotion, or perfume on your breasts or under your arms. These products leave residue on the skin that may create spots on the x-ray.

You may want to consider scheduling the test within two weeks after the end of your menstrual period since that is typically when a woman's breasts are least tender. Avoiding caffeine for a week prior to the examination and taking an over-the-counter pain medication the day of the examination may also reduce breast sensitivity and make the examination more comfortable.

During the procedure

Mammography takes 10 to 15 minutes to complete. You can expect to be at the facility for up to an hour, due to the time it takes to change clothes, have the examination, and allow the technologist to verify that the x-rays are complete.

When you arrive, the technologist will ask you to take off any jewelry that will interfere with the x-ray and remove your clothes above the waist. You will be given a hospital gown that opens in the front.

Before the procedure begins, tell the technologist if you have breast implants, scar tissue from a previous breast surgery, or any area of concern in your breast. Knowing these things will help her perform the mammogram and will help the radiologist read your x-rays more accurately. If you have had prior surgery for breast cancer, the technologist may tape small metal balls to your skin at the site of the scar. This will indicate to the radiologist where you have the highest risk of recurrence.

You will typically stand in front of the mammography machine. The technologist may ask you to relax and take a deep breath as the procedure begins. The technologist will place one of your breasts between two plastic plates, press the plates together to flatten your breast, and take an x-ray. This takes only a few seconds. Your breast is compressed to spread out the tissue and make small abnormalities easier to identify, as well as to prevent motion that would blur the image.

In a screening mammogram, the technologist will usually take two images of each breast, one from the top and one from the side. For a diagnostic mammogram, additional images may be taken. You will change positions slightly for each image. When the examination is complete, you will probably need to wait about five minutes while the x-rays are developed, so the technologist can verify that the pictures are clear and readable.

Generally, mammography is uncomfortable but rarely painful. Some women do find the procedure painful, however, because the x-ray plates are compressed firmly.

After the procedure

You can resume your normal activities immediately after your mammogram.

Additional resources

American Cancer Society (ACS): Mammograms and Other Breast Imaging Procedures

MedlinePlus, U.S. National Library of Medicine, National Institutes of Health: MedlinePlus Interactive Tutorials: Mammogram

Memorial Sloan-Kettering Cancer Center (MSKCC): Breast Cancer Screening Guidelines

National Cancer Institute (NCI): Screening Mammograms: Questions and Answers

RadiologyInfo (Public information website of the Radiological Society of North America and the American College of Radiology): Mammography

WebMD: Mammogram

More Information

Cancer.Net Guide to Breast Cancer

Creative Ways to Promote Cancer Screening

Last Updated: April 10, 2007